0004133373@mcimail.com (Donald E. Kimberlin) (02/18/91)
In article (Digest v11,iss127), Gabe Wiener <gabe@sirius.ctr. columbia.edu> asks: > Has anything ... ever appeared regarding the history of DDD? If not, > could someone in the know post a brief synopsis of its history? Certainly, there are myopic, self-satisfying "histories" published by the various parties involved, giving readers the biased view that one and only one corporation accomplished the job. And, there are the endless references in the technical journals of the participants that have no connected thread. The one world book published by the CCITT, "From Semaphore to Satellite," has to avoid references to commercial firms due to the CCITT's international political nature, so I'm prone to respond that there really isn't any. Topics of how the telecommunications powers of the world interface hasn't yet appealed to students of business or their writers. That groundwork laid, the originator of subscriber-dialed intercity telephone calling was LM Ericsson's manufacturing company in Sweden. By the late 1940's, LME had provided a national network of Subscriber Trunk Dialing (as it is called in British parlance) throughout the network of the Swedish PTT. In keeping with the knowledge Europeans have always had about building export markets, the Swedish PTT (with Ericsson people as their "technical experts") made a "contribution" to the CCITT describing the Ericsson way to further its adoption as a "world standard." This would effectively make it necessary for others to either buy or emulate the Ericsson technology to have compatible interfaces to other nations. In that era, America and its monopoly Bell System were so insular that there was no notion of any need to be compatible with the rest of the world. Trunks between the US and other nations were minimal, operating as manual ringdown circuits on HF (shortwave) radio, and the world of business communicated by mail and Telex, anyway ... so why have much concern for the reports from some "international standards body" that the U.S. didn't need to worry about? However, the U.S. had a growing domestic market for intercity telephone calling, as "the phone" became truly ubiquitous. Completing the volume of calls between cities and across the nation appeared to loom as large a problem as the bankers faced clearing checks manually. If something wasn't done, it would soon require every worker in the nation to merely connect the intercity telephone calls, and the bankers foresaw the entire population would soon have to become bank clerks. Clearly, both could not employ the entire population. AT&T had been studying this problem, and knew that subscribers would soon have to dial their own calls across the country. The proposed project forecasts of how soon were not pleasing to Fred Kappel, then Chairman of AT&T. In a move previously unheard in American business and the Bell System, Kappel went to Sweden to see for himself that Ericsson had indeed completed a network. On his return home, he unstuck the problem by decree that AT&T would, indeed, accomplish the same. Solving the technical problems was, of course, up to Bell Labs. They had a choice to make or buy. Give an engineer a choice of this sort, and the answer is obvious. Bell Labs argued it should be permitted to design a network to suit the "unique' needs of the American telephone network; that it could do so by Kappel's deadline. And, like any non-technologist boss, Kappel let them do it. The Bell Labs rationale was that the Ericsson method contained many costs and functions that Bell Labs could avoid. For example, the Ericsson method used transmitted no tones on an idle trunk to avoid overloading multichannel carrier systems, requiring a complex relay logic method to initiate a call request; it used two tones through filters for a disconnect, to avoid problems with speech making a trunk "talk off" into a disconnect, and it used compelled digit signalling, in which the reciever confirmed each digit back to the sender, to avoid errors in number transmission during call set-up. Since Bell had monopoly control of its domestic network (the only one important to it in that era), it could get away with a single tone transmitted at a low level on an idle trunk, and control the digit transmission in ways that would minimize errors. There was no consideration for interfacing with other nations' networks. So, the Bell way became the "standard" for the US, Canada and portions of Mexico ... the region of Bell hegemony of the time. The Bell term became "Direct Distance Dialing," or DDD. Meantime, the rest of the world agreed on and standardized the Ericsson method, effectively making North American "standard" products pariahs in world trade. Among the "features" of the Bell method at the time were a numbering plan that had a finite number of digits, so relay logic could determine the end of dialing by counting digits, and the use of 0 or 1 in the leading "area code," to identify it as such. Thus, the Bell Labs "home grown" way, replete with a decade or so of problems and modifications to minimize "talk off" and crosstalk on multichannel carrier systems caused by maladustment of levels, became the North American norm. Meantime, the Ericsson way, with an open-ended numbering plan that could fit any nation and less reason to cause crosstalk became the "world standard." America's technological insularity showed through the entire era. Perhaps the most visible incident was the opening of the first automatic transatlantic trunks to Belgium. On the appointed day, trunks terminating at White Plains, NY were connected over to automatic switching ports. They didn't work, because the White Plains end had Bell-type signaling, while the Belgian end had "world-standard" Ericsson-type signalling. No amount of arguing from the Americans could get the Belgians to agree to using the non-standard American stuff. There was a rush in which Bell Labs devised some "applique units" (Bell jargon for an adapter/converter more complex than a simple relay) that converted between the two and installed them in White Plains. To this day, we still use the "Bell way' domestically, which requires a Bell-style switching machine to have "special" functions for international operations. The CCITT has recognized the "Bell way" for world regional use where PTT's of a region agree among themselves to use it, calling it CCITT Signalling System R-2. About the only place R-2 found any acceptance has been in the Pan-African plan, and that choice seems largely to have been one selected for political reasons in which the Africans showed their former colonial masters they had some choice. It didn't result in any market for Bell. They at the time weren't interested in selling export markets, so the Africans went to others who simply adapted and negotiated the matter to a sale, once again swiping market that had been made for the Americans. If this overview seems acerbic, it is intended that way, for I was there, watching America inflate its domestic ego while letting its huge economic dog gather yet another case of fleas. DDD is but one of the many ways we have let short-sighted accountants set us up for the problems we have today.